Linux Ethernet Bridging - Mar 2017 - [Bridge] [PATCH net] bridge: ebtables: fix reception of frames DNAT-ed to bridge device

On Wed, Mar 15, 2017 at 07:15:39PM +0100, Pablo Neira Ayuso
wrote:
> Could you update ebtables dnat to check if the ethernet address
> matches the one of the input bridge interface, so we mangle the
> ->pkt_type accordingly from there, instead of doing this from the
> core?
Actually, that was the approach I thought about and went for first
(and it would probably work for me). Just checking against the
bridge device's net_device::dev_addr.

I scratched it though, as I was afraid that the issue might still
exist for people using some other upper device on top of the bridge
device. For instance, macvlan? And iterating over the
net_device::dev_addrs list seemed too costly for fast path to me.

On Wed, Mar 15, 2017 at 10:16:19PM +0100, Linus L?ssing
wrote:
> On Wed, Mar 15, 2017 at 07:15:39PM +0100, Pablo Neira Ayuso wrote:
> > Could you update ebtables dnat to check if the ethernet address
> > matches the one of the input bridge interface, so we mangle the
> > ->pkt_type accordingly from there, instead of doing this from the
> > core?
> 
> Actually, that was the approach I thought about and went for first
> (and it would probably work for me). Just checking against the
> bridge device's net_device::dev_addr.
> 
> I scratched it though, as I was afraid that the issue might still
> exist for people using some other upper device on top of the bridge
> device. For instance, macvlan? And iterating over the
> net_device::dev_addrs list seemed too costly for fast path to me.
I was more thinking of following the simple approach that we follow in
ebt_redirect_tg() by taking the input interface.

Anyway, I'm ok with this.